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SW_Explorer's avatar
SW_Explorer
Explorer
Jul 30, 2020

Battery Drain Help Please

I'm looking for some electrical advice please. I have a 2005 F350 Diesel and a 2002 AF 1080 truck camper. I keep the camper plugged in to shore power when not in use. Last night while getting ready to head out I fount the truck batteries completely dead. Nothing was on in the truck as far as lights or 12v accessories. The batteries are only 3 months old, as this happened the last time we tried to go out so I replaced them thinking they were due.

Prior to this summer we have never had an issue.

Any thoughts on what could be draining the truck batteries? The camper shouldn't through the umbilible, right?

For what it's worth the camper batteries were also replaced about a month ago, too.

I'm trying to figure out if I should take it to the mechanic or RV repair shop

Thanks in advance for the help as always.
Truck Campers
  • mbloof's avatar
    mbloof
    Explorer
    Jul 30, 2020
    Bert the Welder wrote:
    My new truck battery got killed a few days after being in the truck. Turns out the radio had got south and was draining it. Had to pull the fuse. No more radio, but no more drain on the replacement. My cheap one way battery shunt got stuck one time years ago too and drained the truck. Now I always unplug just in case.


    My old truck developed a load that would kill a fully charged battery in a matter of weeks. After lots of probing I finally put a knife switch on the positive terminal and got in the habit of disconnecting the battery each time I was not going to use the truck the same day.

    Overkill but no more dead batteries.


    - Mark0.
  • Bert_the_Welder's avatar
    Bert_the_Welder
    Explorer II
    Jul 30, 2020
    My new truck battery got killed a few days after being in the truck. Turns out the radio had got south and was draining it. Had to pull the fuse. No more radio, but no more drain on the replacement. My cheap one way battery shunt got stuck one time years ago too and drained the truck. Now I always unplug just in case.
  • Grit_dog's avatar
    Grit_dog
    Navigator
    Jul 30, 2020
    OP, be more descriptive with your issue.
    Camper plugged in to truck? Presume yes by your post.
    Camper batteries fully charged or dead too?
    Truck wont drain from camper if the camper batteries are charged/ charging.
    So issue is likely with the truck. IMO.

    Also not good to just leave camper batteries on a converter unless it’s a smart charger. It’ll overcharge
  • Notakwanon's avatar
    Notakwanon
    Explorer
    Jul 30, 2020
    The smoke detectors, pilot lights on plugs, etc. in the camper can definitely drain the two batteries in a diesel over the course of two weeks of dis-use, unless you have a battery isolator under the hood, because it has happened to me. But I am puzzled. If the camper is plugged into shore power, the batteries should stay topped up, suggesting a charging problem. Check for a blown fuse in the power management box, or a breaker in the wrong position. Likely something simple, but not necessarily easy to find.
  • joerg68's avatar
    joerg68
    Nomad III
    Jul 30, 2020
    ... and then do the same measurement with the camper disconnected. That way you can tell if the camper can be the source.

    Once you have this measuring thing sorted out, you can start pulling individual fuses until the draw goes away. That way you can usually further isolate the culprit.

    How long had the truck been sitting? Why do you believe the camper causes this? Was the camper battery also dead, or fully charged as would be expected?
    Were all lights out on the truck? All doors properly closed? The door switches go bad pretty frequently.
    One possible issue can be the on board computer not "going to sleep", because it senses "something" is not properly turned off. With the resulting draw, it can drain a battery within a week or two, even when you think everything is turned off.
  • Sjm9911's avatar
    Sjm9911
    Explorer
    Jul 30, 2020
    Your plugging the truck into the camper? Not all TV have a shut off so the camper could have drained the batteries. I would charge everything up and disconnect the cord and see what happens. Not really sure how the truck campers work.
  • sbryan's avatar
    sbryan
    Explorer II
    Jul 30, 2020
    Not sure about the 2005 but my 2013 F350 diesel has a battery disconnect built in. There is a parasitic drain on the truck battery from things like clocks and other electronics but that shouldn't be an issue in 3 months time. I assume you have two batteries since it is a diesel. I keep my truck on a battery tender because it is often months between trips. Disconnect the battery terminal and measure the current draw with a meter. That will give you some idea of how large a drain there is. That is where I would start my trouble shooting. If there any significant drain something is amiss somewhere.

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